1. Field of the Invention
This invention relates to a zoom lens system and is more particularly directed to a zoom lens system having a relatively large aperture whereby the system is suitable for use in a projector.
2. Description of the Prior Art
In a projector, a brighter lens system is achieved when more light from the source falls on the screen, and the projected images are magnified and thus are easier to view. However, as the brightness of the lens system increases, the apparent depth of focus becomes narrower, and it becomes necessary to provide better correction of aberrations and better balance between the components of the system as compared to a darker lens system.